Sandbox

SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = '0ZVF-GX75-MA6F-GL5E-WQW7-F27T-T6B2-US9J' 
  AND product_id = 5 
  AND expires_at > 1777272747 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00033

JSON explain

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