SELECT 
  pfv.feature_id, 
  pfv.product_id, 
  pfv.variant_id, 
  gp.group_id 
FROM 
  cscart_product_features_values AS pfv 
  INNER JOIN cscart_product_variation_group_products AS gp ON pfv.product_id = gp.product_id 
  INNER JOIN cscart_product_variation_group_features AS gpf ON gpf.group_id = gp.group_id 
  AND gpf.feature_id = pfv.feature_id 
WHERE 
  pfv.lang_code = 'ru' 
  AND gp.group_id IN (
    183, 35, 186, 185, 149, 205, 136, 135, 
    123, 122, 180, 208, 224, 207, 218
  )

Query time 0.00108

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "42.86"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "gp",
          "access_type": "range",
          "possible_keys": [
            "PRIMARY",
            "idx_group_id"
          ],
          "key": "idx_group_id",
          "used_key_parts": [
            "group_id"
          ],
          "key_length": "3",
          "rows_examined_per_scan": 34,
          "rows_produced_per_join": 34,
          "filtered": "100.00",
          "index_condition": "(`test_uchur_k`.`gp`.`group_id` in (183,35,186,185,149,205,136,135,123,122,180,208,224,207,218))",
          "cost_info": {
            "read_cost": "15.66",
            "eval_cost": "3.40",
            "prefix_cost": "19.06",
            "data_read_per_join": "544"
          },
          "used_columns": [
            "product_id",
            "group_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "gpf",
          "access_type": "ref",
          "possible_keys": [
            "PRIMARY",
            "idx_group_id"
          ],
          "key": "idx_group_id",
          "used_key_parts": [
            "group_id"
          ],
          "key_length": "3",
          "ref": [
            "test_uchur_k.gp.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 34,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "8.50",
            "eval_cost": "3.40",
            "prefix_cost": "30.96",
            "data_read_per_join": "3K"
          },
          "used_columns": [
            "feature_id",
            "group_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "pfv",
          "access_type": "ref",
          "possible_keys": [
            "PRIMARY",
            "fl",
            "lang_code",
            "product_id",
            "fpl",
            "idx_product_feature_variant_id"
          ],
          "key": "fpl",
          "used_key_parts": [
            "feature_id",
            "product_id",
            "lang_code"
          ],
          "key_length": "12",
          "ref": [
            "test_uchur_k.gpf.feature_id",
            "test_uchur_k.gp.product_id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 34,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "8.50",
            "eval_cost": "3.40",
            "prefix_cost": "42.86",
            "data_read_per_join": "26K"
          },
          "used_columns": [
            "feature_id",
            "product_id",
            "variant_id",
            "lang_code"
          ]
        }
      }
    ]
  }
}

Result

feature_id product_id variant_id group_id
3 82 6 35
193 51076 1364 122
193 51073 1361 122
193 51072 1360 122
193 51074 1362 122
193 51075 1363 122
193 22711 1359 122
193 22710 1358 123
193 51077 1359 123
193 51080 1362 123
193 51078 1360 123
193 51079 1361 123
193 51139 1362 135
193 51138 1361 135
193 51137 1360 135
193 51136 1359 135
193 51135 1358 135
193 40 1357 135
193 51144 1362 136
193 51143 1361 136
193 51142 1360 136
193 51141 1359 136
193 51140 1358 136
193 39 1357 136
193 51205 1360 149
193 51204 1359 149
193 51203 1358 149
193 51202 1374 149
193 125 1357 149
193 17 1373 180
193 56 1373 183
193 51295 1376 185
193 117 1375 185
193 116 1375 186
193 106 1373 205
193 58 1373 207
193 57 1373 208
193 5 1373 218
193 51349 1386 224
193 122 1385 224