Sandbox

SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = '2LY9-S2QM-7G8M-3OR3-05JT-5X5J-SZ71-40P9' 
  AND product_id = 100 
  AND expires_at > 1777907163 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00022

JSON explain

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