SELECT 
  product_id, 
  amount 
FROM 
  cscart_warehouses_sum_products_amount 
WHERE 
  1 
  AND product_id IN (
    276671, 276672, 276673, 276674, 276675, 
    276676, 276677, 276678, 276679, 276680, 
    276681, 276682
  )

Query time 0.00026

JSON explain

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