SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b59ae682595ed1b4422c53d117cc202031081e78fc8f72e41357019494254561' 
  AND token = 'QDO7PpnSy+7Xd33AYZFktaSfqETEhsjhAcQ4AbulGpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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