SELECT 
  1 
FROM 
  cscart_june_setupec_print_temp_designs 
WHERE 
  session_id = 'Z2JD-RE4G-1E8Y-28IZ-ZBBC-DW24-GKFQ-MQE6' 
  AND product_id = 82 
  AND expires_at > 1781893482 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00027

JSON explain

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