SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = '8MNU-B05V-9EA0-PFV9-649F-Z4DL-SX7Y-L4A5' 
  AND product_id = 94 
  AND expires_at > 1777206168 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00033

JSON explain

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