SELECT 
  pf.feature_id, 
  pf.company_id, 
  pf.feature_type, 
  pf.parent_id, 
  pf.display_on_product, 
  pf.display_on_catalog, 
  pf.display_on_header, 
  pf.categories_path, 
  pf.status, 
  pf.comparison, 
  pf.position, 
  pf.purpose, 
  pf.feature_style, 
  pf.filter_style, 
  pf.feature_code, 
  pfd.description, 
  pfd.lang_code, 
  pfd.prefix, 
  pfd.suffix, 
  pfd.full_description, 
  pfv.value, 
  pfv.variant_id, 
  pfv.value_int, 
  pfv.product_id 
FROM 
  cscart_product_features_values AS pfv 
  LEFT JOIN cscart_product_features AS pf ON pfv.feature_id = pf.feature_id 
  LEFT JOIN cscart_product_features_descriptions AS pfd ON pfd.feature_id = pf.feature_id 
  AND pfd.lang_code = 'en' 
WHERE 
  1 = 1 
  AND pfv.product_id IN (
    12713, 12712, 12711, 12710, 12709, 12708, 
    12707, 12706, 12705, 12684, 12685, 
    12686, 12687, 12688, 12689, 12690, 
    12691, 12692, 12693, 12694, 12695, 
    12696, 12697, 12698, 12699, 12700, 
    12701, 12702, 12703, 12704
  ) 
  AND pfv.lang_code = 'en' 
  AND pf.feature_code IN ('Brand', 'ISBN', 'GTIN', 'MPN')

Query time 0.00475

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "980.29"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "pfv",
          "access_type": "range",
          "possible_keys": [
            "PRIMARY",
            "fl",
            "lang_code",
            "product_id",
            "fpl",
            "idx_product_feature_variant_id"
          ],
          "key": "idx_product_feature_variant_id",
          "used_key_parts": [
            "product_id"
          ],
          "key_length": "3",
          "rows_examined_per_scan": 1357,
          "rows_produced_per_join": 739,
          "filtered": "54.46",
          "index_condition": "((`test2_gaseus`.`pfv`.`product_id` in (12713,12712,12711,12710,12709,12708,12707,12706,12705,12684,12685,12686,12687,12688,12689,12690,12691,12692,12693,12694,12695,12696,12697,12698,12699,12700,12701,12702,12703,12704)) and (`test2_gaseus`.`pfv`.`lang_code` = 'en'))",
          "cost_info": {
            "read_cost": "544.26",
            "eval_cost": "73.90",
            "prefix_cost": "618.16",
            "data_read_per_join": "571K"
          },
          "used_columns": [
            "feature_id",
            "product_id",
            "variant_id",
            "value",
            "value_int",
            "lang_code"
          ]
        }
      },
      {
        "table": {
          "table_name": "pf",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "feature_id"
          ],
          "key_length": "3",
          "ref": [
            "test2_gaseus.pfv.feature_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 295,
          "filtered": "40.00",
          "cost_info": {
            "read_cost": "184.76",
            "eval_cost": "29.56",
            "prefix_cost": "876.83",
            "data_read_per_join": "348K"
          },
          "used_columns": [
            "feature_id",
            "feature_code",
            "company_id",
            "purpose",
            "feature_style",
            "filter_style",
            "feature_type",
            "categories_path",
            "parent_id",
            "display_on_product",
            "display_on_catalog",
            "display_on_header",
            "status",
            "position",
            "comparison"
          ],
          "attached_condition": "(`test2_gaseus`.`pf`.`feature_code` in ('Brand','ISBN','GTIN','MPN'))"
        }
      },
      {
        "table": {
          "table_name": "pfd",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "feature_id",
            "lang_code"
          ],
          "key_length": "9",
          "ref": [
            "test2_gaseus.pfv.feature_id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 295,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "73.90",
            "eval_cost": "29.56",
            "prefix_cost": "980.29",
            "data_read_per_join": "702K"
          },
          "used_columns": [
            "feature_id",
            "description",
            "full_description",
            "prefix",
            "suffix",
            "lang_code"
          ]
        }
      }
    ]
  }
}