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SELECT 
  product_id, 
  amount 
FROM 
  cscart_warehouses_sum_products_amount 
WHERE 
  1 
  AND product_id IN (
    276695, 276696, 276697, 276698, 276699, 
    276700, 276701, 276702, 276703, 276704, 
    276705, 276706
  )

Query time 0.00017

JSON explain

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