Sandbox

SELECT 
  product_id, 
  amount 
FROM 
  cscart_warehouses_sum_products_amount 
WHERE 
  1 
  AND product_id IN (
    276659, 276660, 276661, 276662, 276663, 
    276664, 276665, 276666, 276667, 276668, 
    276669, 276670
  )

Query time 0.00016

JSON explain

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