Sandbox

SELECT 
  1 
FROM 
  cscart_june_setupec_print_temp_designs 
WHERE 
  session_id = 'ECMT-3LM5-QL9J-117S-1AO1-KQ9A-8382-YAY8' 
  AND product_id = 17 
  AND expires_at > 1781762690 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00018

JSON explain

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