Sandbox

SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = 'A1SC-IMQN-8M3Q-U1TB-VJXL-9T33-GKI1-AXA1' 
  AND product_id = 248 
  AND expires_at > 1777123671 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00025

JSON explain

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