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 (337, 1562, 1563, 1564) 
  AND pfv.lang_code = 'en' 
  AND pf.feature_code IN ('Brand', 'ISBN', 'GTIN', 'MPN')

Query time 0.00089

JSON explain

{
  "query_block": {
    "select_id": 1,
    "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",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 33,
      "filtered": 75.758,
      "index_condition": "pfv.product_id in (337,1562,1563,1564) and pfv.lang_code = 'en'"
    },
    "table": {
      "table_name": "pf",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["feature_id"],
      "ref": ["herbaria_cscart_4_18.pfv.feature_id"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "pf.feature_code in ('Brand','ISBN','GTIN','MPN')"
    },
    "table": {
      "table_name": "pfd",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["feature_id", "lang_code"],
      "ref": ["herbaria_cscart_4_18.pfv.feature_id", "const"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "trigcond(pfd.lang_code = 'en')"
    }
  }
}