SELECT 
  1 
FROM 
  cscart_june_setupec_print_temp_designs 
WHERE 
  session_id = '5DCY-ETWG-BK48-A9QA-6IR5-VL94-Q38I-54A2' 
  AND product_id = 131 
  AND expires_at > 1781894835 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00026

JSON explain

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