Sandbox

SELECT 
  1 
FROM 
  cscart_ec_print_temp_designs 
WHERE 
  session_id = 'H107-1YZ5-0D0X-EUXN-IXP1-G2A5-H594-ONME' 
  AND product_id = 240 
  AND expires_at > 1770174520 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00049

JSON explain

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