Sandbox

SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = 'Y4BA-W95D-O2PZ-65X5-B269-K1VP-SO5W-CUUW' 
  AND product_id = 15 
  AND expires_at > 1777128302 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00051

JSON explain

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