SELECT 
  product_id, 
  feature_id, 
  variant_id 
FROM 
  cscart_product_features_values 
WHERE 
  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 feature_id IN (553, 625, 624, 627, 628) 
  AND lang_code = 'en'

Query time 0.00501

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "10.28"
    },
    "table": {
      "table_name": "cscart_product_features_values",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "fl",
        "lang_code",
        "product_id",
        "fpl",
        "idx_product_feature_variant_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "feature_id",
        "product_id",
        "variant_id",
        "lang_code"
      ],
      "key_length": "15",
      "rows_examined_per_scan": 29,
      "rows_produced_per_join": 29,
      "filtered": "100.00",
      "using_index_for_skip_scan": true,
      "cost_info": {
        "read_cost": "7.38",
        "eval_cost": "2.90",
        "prefix_cost": "10.28",
        "data_read_per_join": "22K"
      },
      "used_columns": [
        "feature_id",
        "product_id",
        "variant_id",
        "lang_code"
      ],
      "attached_condition": "((`test2_gaseus`.`cscart_product_features_values`.`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`.`cscart_product_features_values`.`feature_id` in (553,625,624,627,628)) and (`test2_gaseus`.`cscart_product_features_values`.`lang_code` = 'en'))"
    }
  }
}