SELECT 
  cscart_product_feature_variant_descriptions.variant, 
  cscart_product_feature_variants.variant_id, 
  cscart_product_feature_variants.feature_id, 
  cscart_product_features_values.variant_id as selected, 
  cscart_product_features.feature_type, 
  cscart_seo_names.name as seo_name, 
  cscart_seo_names.path as seo_path, 
  cscart_product_feature_variants.color, 
  cscart_product_features_values.value_int, 
  cscart_product_feature_variants.abt__ut2_multicolor, 
  cscart_product_feature_variants.abt__ut2_color_style 
FROM 
  cscart_product_feature_variants 
  LEFT JOIN cscart_product_feature_variant_descriptions ON cscart_product_feature_variant_descriptions.variant_id = cscart_product_feature_variants.variant_id 
  AND cscart_product_feature_variant_descriptions.lang_code = 'kk' 
  INNER JOIN cscart_product_features_values ON cscart_product_features_values.variant_id = cscart_product_feature_variants.variant_id 
  AND cscart_product_features_values.lang_code = 'kk' 
  AND cscart_product_features_values.product_id = 51 
  AND cscart_product_features_values.feature_id = cscart_product_feature_variants.feature_id 
  LEFT JOIN cscart_product_features ON cscart_product_features.feature_id = cscart_product_feature_variants.feature_id 
  LEFT JOIN cscart_seo_names ON cscart_seo_names.object_id = cscart_product_feature_variants.variant_id 
  AND cscart_seo_names.type = 'e' 
  AND cscart_seo_names.dispatch = '' 
  AND cscart_seo_names.lang_code = 'ru' 
  AND (
    cscart_seo_names.company_id = 1 
    OR cscart_seo_names.company_id = 0
  ) 
WHERE 
  1 
  AND cscart_product_feature_variants.feature_id IN (
    1, 55, 56, 6, 57, 58, 59, 10, 82, 84, 47, 
    60, 85, 86, 67, 49, 13, 87, 3, 88, 39, 65, 
    66
  ) 
GROUP BY 
  cscart_product_feature_variants.variant_id 
ORDER BY 
  cscart_product_feature_variants.position, 
  cscart_product_feature_variant_descriptions.variant

Query time 0.00568

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "58.60"
    },
    "ordering_operation": {
      "using_filesort": true,
      "grouping_operation": {
        "using_temporary_table": true,
        "using_filesort": false,
        "nested_loop": [
          {
            "table": {
              "table_name": "cscart_product_features_values",
              "access_type": "range",
              "possible_keys": [
                "PRIMARY",
                "fl",
                "variant_id",
                "lang_code",
                "product_id",
                "fpl",
                "idx_product_feature_variant_id"
              ],
              "key": "fpl",
              "used_key_parts": [
                "feature_id",
                "product_id",
                "lang_code"
              ],
              "key_length": "12",
              "rows_examined_per_scan": 28,
              "rows_produced_per_join": 28,
              "filtered": "100.00",
              "index_condition": "((`test_uchur_k`.`cscart_product_features_values`.`product_id` = 51) and (`test_uchur_k`.`cscart_product_features_values`.`feature_id` in (1,55,56,6,57,58,59,10,82,84,47,60,85,86,67,49,13,87,3,88,39,65,66)) and (`test_uchur_k`.`cscart_product_features_values`.`lang_code` = 'kk'))",
              "cost_info": {
                "read_cost": "15.56",
                "eval_cost": "2.80",
                "prefix_cost": "18.36",
                "data_read_per_join": "21K"
              },
              "used_columns": [
                "feature_id",
                "product_id",
                "variant_id",
                "value_int",
                "lang_code"
              ]
            }
          },
          {
            "table": {
              "table_name": "cscart_product_feature_variants",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY",
                "feature_id"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "variant_id"
              ],
              "key_length": "3",
              "ref": [
                "test_uchur_k.cscart_product_features_values.variant_id"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 14,
              "filtered": "51.77",
              "cost_info": {
                "read_cost": "7.00",
                "eval_cost": "1.45",
                "prefix_cost": "28.16",
                "data_read_per_join": "22K"
              },
              "used_columns": [
                "variant_id",
                "feature_id",
                "color",
                "position",
                "abt__ut2_color_style",
                "abt__ut2_multicolor"
              ],
              "attached_condition": "(`test_uchur_k`.`cscart_product_feature_variants`.`feature_id` = `test_uchur_k`.`cscart_product_features_values`.`feature_id`)"
            }
          },
          {
            "table": {
              "table_name": "cscart_product_features",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "feature_id"
              ],
              "key_length": "3",
              "ref": [
                "test_uchur_k.cscart_product_features_values.feature_id"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 14,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "3.62",
                "eval_cost": "1.45",
                "prefix_cost": "33.23",
                "data_read_per_join": "27K"
              },
              "used_columns": [
                "feature_id",
                "feature_type"
              ]
            }
          },
          {
            "table": {
              "table_name": "cscart_product_feature_variant_descriptions",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "variant_id",
                "lang_code"
              ],
              "key_length": "9",
              "ref": [
                "test_uchur_k.cscart_product_features_values.variant_id",
                "const"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 14,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "3.62",
                "eval_cost": "1.45",
                "prefix_cost": "38.31",
                "data_read_per_join": "45K"
              },
              "used_columns": [
                "variant_id",
                "variant",
                "lang_code"
              ]
            }
          },
          {
            "table": {
              "table_name": "cscart_seo_names",
              "access_type": "ref",
              "possible_keys": [
                "PRIMARY",
                "dispatch"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "object_id",
                "type",
                "dispatch",
                "lang_code"
              ],
              "key_length": "206",
              "ref": [
                "test_uchur_k.cscart_product_features_values.variant_id",
                "const",
                "const",
                "const"
              ],
              "rows_examined_per_scan": 4,
              "rows_produced_per_join": 57,
              "filtered": "100.00",
              "index_condition": "<if>(is_not_null_compl(cscart_seo_names), ((`test_uchur_k`.`cscart_seo_names`.`company_id` = 1) or (`test_uchur_k`.`cscart_seo_names`.`company_id` = 0)), true)",
              "cost_info": {
                "read_cost": "14.50",
                "eval_cost": "5.80",
                "prefix_cost": "58.60",
                "data_read_per_join": "98K"
              },
              "used_columns": [
                "name",
                "object_id",
                "company_id",
                "type",
                "dispatch",
                "path",
                "lang_code"
              ]
            }
          }
        ]
      }
    }
  }
}

Result

variant variant_id feature_id selected feature_type seo_name seo_path color value_int abt__ut2_multicolor abt__ut2_color_style
100% полиэстер 128 59 128 M #ffffff #ffffff default
10000 261 84 261 S default
10000 259 82 259 S default
2 куртки и штаны 268 87 268 S default
3.9 269 88 269 S default
ARDAH-SHIELD 262 47 262 M default
BULCHUT 3в1 258 55 258 S default
Durable Water-Resistant Teflon Shield+ 266 85 266 S default
DWR пропитка 263 47 263 M default
Sorona 260 10 260 M default
SORONA-DUPONT 264 47 264 M default
SYSTAR-SEAL 265 47 265 M default
TAAS 238 39 238 S #4f5b5c #ffffff thumbnail
Да 157 49 157 S #ffffff #ffffff default
Да 129 60 129 S #ffffff #ffffff default
до -35 267 86 267 S default
Есть 150 67 150 S #ffffff #ffffff default
Зима 57 6 57 M #ffffff #ffffff default
Камуфляж + Логотип 234 65 234 M default
Китай 147 66 147 S #ffffff #ffffff default
Мужской 123 57 123 M #ffffff #ffffff default
Охота 127 56 127 M #ffffff #ffffff default
Полиэстер 125 58 125 M #ffffff #ffffff default
размер XL 26 3 26 S default
Рыбалка 149 56 149 M default
Туризм 120 56 120 M default
Шнурок 64 13 64 S default
UCHUR 1 1 1 E uchur-ru default