SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = 'D36E-5LAO-7W0M-3CF7-JIZB-86IS-J7S9-JD9T' 
  AND product_id = 55 
  AND expires_at > 1777278026 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00068

JSON explain

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