SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '648b250a579f545d8c893cf59fa90f8ba3d0b0f279e954c71a81a4e7bd9b41c5' 
  AND token = 'hqzeK5yl5UD2+aUyVDM+/2Rr04zJZf13bYfpGyjpgI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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