SELECT 
  feature_id, 
  variant_id, 
  value, 
  value_int 
FROM 
  cscart_product_features_values 
WHERE 
  product_id = 13468 
  AND lang_code = 'en'

Query time 0.00094

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "438.00"
    },
    "table": {
      "table_name": "cscart_product_features_values",
      "access_type": "ref",
      "possible_keys": [
        "lang_code",
        "product_id",
        "idx_product_feature_variant_id"
      ],
      "key": "product_id",
      "used_key_parts": [
        "product_id"
      ],
      "key_length": "3",
      "ref": [
        "const"
      ],
      "rows_examined_per_scan": 365,
      "rows_produced_per_join": 18,
      "filtered": "4.94",
      "index_condition": "(`webmarco`.`cscart_product_features_values`.`lang_code` = 'en')",
      "cost_info": {
        "read_cost": "365.00",
        "eval_cost": "3.61",
        "prefix_cost": "438.00",
        "data_read_per_join": "13K"
      },
      "used_columns": [
        "feature_id",
        "product_id",
        "variant_id",
        "value",
        "value_int",
        "lang_code"
      ]
    }
  }
}

Result

feature_id variant_id value value_int
557 0 Prices cannot be displayed because it depends on the service you are interested in. Contact us for information.
611 8188
618 1538
619 1542
620 4302
621 7131
622 7134
741 38290
834 59755
835 59704
851 59915