SELECT 
  product_id, 
  amount 
FROM 
  cscart_warehouses_sum_products_amount 
WHERE 
  1 
  AND product_id IN (
    276446, 276447, 276448, 276449, 276450, 
    276451, 276452, 276453, 276454, 276455, 
    276456, 276457, 276458, 276459, 276460, 
    276461, 276462, 276463, 276464, 276465
  )

Query time 0.00057

JSON explain

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