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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 (
    5621, 5622, 5623, 5624, 5625, 5626, 5627, 
    5628, 5629, 5630, 5631, 5632
  ) 
  AND cscart_product_review_prepared_data.storefront_id = 0

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "Impossible WHERE noticed after reading const tables"
  }
}