SELECT 
  1 
FROM 
  cscart_aprilec_print_temp_designs 
WHERE 
  session_id = '6QWE-K8H6-GOV3-K30L-5ON7-1P2L-1DM0-WZ1K' 
  AND product_id = 202 
  AND expires_at > 1777123621 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00029

JSON explain

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