Sandbox

SELECT 
  1 
FROM 
  cscart_june_setupec_print_temp_designs 
WHERE 
  session_id = '8T3W-2AH2-CF3B-MK14-QPBP-LSGP-LNQE-KVTC' 
  AND product_id = 211 
  AND expires_at > 1781894499 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00035

JSON explain

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