SELECT 
  product_id, 
  amount 
FROM 
  cscart_warehouses_sum_products_amount 
WHERE 
  1 
  AND product_id IN (
    276618, 276619, 276620, 276621, 276622, 
    276623, 276624, 276625, 276626, 276627, 
    276628, 276629, 276630, 276631, 276632
  )

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}