SELECT 
  1 
FROM 
  cscart_ec_print_temp_designs 
WHERE 
  session_id = '2K29-JPPD-76VK-WJ0M-5P1T-2Z2A-7ACO-0RZ8' 
  AND product_id = 153 
  AND expires_at > 1771079736 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00069

JSON explain

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