SELECT 
  cscart_product_feature_variants.variant_id, 
  cscart_product_feature_variants.position, 
  cscart_product_feature_variants.color, 
  cscart_product_feature_variant_descriptions.variant 
FROM 
  cscart_product_feature_variants 
  LEFT JOIN cscart_product_feature_variant_descriptions ON cscart_product_feature_variants.variant_id = cscart_product_feature_variant_descriptions.variant_id 
  AND cscart_product_feature_variant_descriptions.lang_code = 'ru' 
WHERE 
  cscart_product_feature_variants.variant_id IN (
    3, 26, 50, 57, 320, 120, 122, 127, 149, 
    123, 414, 146, 147, 257, 125, 366, 367, 
    31, 299, 154, 296, 298, 32, 489, 33, 165, 
    121, 148, 42, 58, 173, 172, 176, 43, 155, 
    44, 503, 152, 502, 59, 252, 234
  ) 
ORDER BY 
  cscart_product_feature_variants.position ASC, 
  cscart_product_feature_variant_descriptions.variant ASC

Query time 0.00090

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "44.11"
    },
    "ordering_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_product_feature_variants",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "variant_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 42,
            "rows_produced_per_join": 42,
            "filtered": "100.00",
            "index_condition": "(`test_uchur_k`.`cscart_product_feature_variants`.`variant_id` in (3,26,50,57,320,120,122,127,149,123,414,146,147,257,125,366,367,31,299,154,296,298,32,489,33,165,121,148,42,58,173,172,176,43,155,44,503,152,502,59,252,234))",
            "cost_info": {
              "read_cost": "25.21",
              "eval_cost": "4.20",
              "prefix_cost": "29.41",
              "data_read_per_join": "64K"
            },
            "used_columns": [
              "variant_id",
              "color",
              "position"
            ]
          }
        },
        {
          "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_feature_variants.variant_id",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 42,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "10.50",
              "eval_cost": "4.20",
              "prefix_cost": "44.11",
              "data_read_per_join": "130K"
            },
            "used_columns": [
              "variant_id",
              "variant",
              "lang_code"
            ]
          }
        }
      ]
    }
  }
}