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SELECT 
  product_id, 
  amount 
FROM 
  cscart_warehouses_sum_products_amount 
WHERE 
  1 
  AND product_id IN (
    276678, 276679, 276680, 276681, 276682, 
    276683, 276684, 276685, 276686, 276687, 
    276688, 276689, 276690, 276691, 276692
  )

Query time 0.00037

JSON explain

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