Using order by VS two conditions on where clause

I have a table like this:

// permlog
+----+----------+-------------+
| id | id_user  |  unix_time  |
+----+----------+-------------+
| 1  | 2353     | 1339412843  |
| 2  | 2353     | 1339412864  |
| 3  | 5462     | 1339412894  |
| 4  | 3422     | 1339412899  |
| 5  | 3422     | 1339412906  |
| 6  | 2353     | 1339412906  |
| 7  | 7785     | 1339412951  |
| 8  | 2353     | 1339413640  |
| 9  | 5462     | 1339413621  |
| 10 | 5462     | 1339414490  |
| 11 | 2353     | 1339414923  |
| 12 | 2353     | 1339419901  |
| 13 | 8007     | 1339424860  |
| 14 | 7785     | 1339424822  |
| 15 | 2353     | 1339424902  |
| 16 | 2353     | 1466272801  |
| 17 | 2353     | 1466272805  |
+----+----------+-------------+

I need to select last row for specific user. I have two queries:

So here is expected result:

/* :id = 5462 */
| 10 | 5462     | 1339414490  |

---

Using order by:

SELECT * FROM permlog WHERE id_user = :id ORDER BY unix_time DESC LIMIT 0, 1;

Using two conditions on where clause:

SELECT *
FROM permlog
WHERE id_user = :id AND unix_time = ( SELECT MAX(unix_time) FROM permlog WHERE id_user = :id);

Which one is better? Or is there a better third option?