SELECT 
  cscart_product_review_prepared_data.product_id AS product_id, 
  cscart_product_review_prepared_data.average_rating AS average_rating, 
  cscart_product_review_prepared_data.reviews_count AS reviews_count 
FROM 
  cscart_product_review_prepared_data 
WHERE 
  cscart_product_review_prepared_data.product_id IN (
    5921, 5559, 5582, 5563, 5577, 5789, 5777, 
    5787, 5913, 5583, 5560, 5562, 5916, 
    5579, 5584, 5773, 5865, 5867, 6334, 
    5786, 6493, 5963, 5863, 6345
  ) 
  AND cscart_product_review_prepared_data.storefront_id = 0

Query time 0.00098

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "1.00"
    },
    "table": {
      "table_name": "cscart_product_review_prepared_data",
      "access_type": "ALL",
      "possible_keys": [
        "PRIMARY"
      ],
      "rows_examined_per_scan": 5,
      "rows_produced_per_join": 5,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "0.50",
        "eval_cost": "0.50",
        "prefix_cost": "1.00",
        "data_read_per_join": "80"
      },
      "used_columns": [
        "product_id",
        "storefront_id",
        "average_rating",
        "reviews_count"
      ],
      "attached_condition": "((`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_review_prepared_data`.`storefront_id` = 0) and (`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_review_prepared_data`.`product_id` in (5921,5559,5582,5563,5577,5789,5777,5787,5913,5583,5560,5562,5916,5579,5584,5773,5865,5867,6334,5786,6493,5963,5863,6345)))"
    }
  }
}