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SELECT 
  product_id, 
  amount 
FROM 
  cscart_warehouses_sum_products_amount 
WHERE 
  1 
  AND product_id IN (
    276647, 276648, 276649, 276650, 276651, 
    276652, 276653, 276654, 276655, 276656, 
    276657, 276658, 276659, 276660, 276661, 
    276662, 276663, 276664, 276665, 276666
  )

Query time 0.00028

JSON explain

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