Sandbox

SELECT 
  product_id, 
  amount 
FROM 
  cscart_warehouses_sum_products_amount 
WHERE 
  1 
  AND product_id IN (
    276509, 276510, 276511, 276512, 276513, 
    276514, 276515, 276516, 276517, 276518, 
    276519, 276520
  )

Query time 0.00043

JSON explain

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