mysql chock problem

gistfile1.txt

mysql> desc gif_user;
+-------------+--------------+------+-----+-------------------+-----------------------------+
| Field       | Type         | Null | Key | Default           | Extra                       |
+-------------+--------------+------+-----+-------------------+-----------------------------+
| guid        | int(11)      | NO   | PRI | NULL              | auto_increment              |
| user_cookie | varchar(500) | NO   | MUL | NULL              |                             |
| gif_id      | int(11)      | NO   |     | NULL              |                             |
| createdon   | timestamp    | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
| period      | int(11)      | YES  |     | NULL              |                             |


mysql> select count(*) from  gif_stash;
+----------+
| count(*) |
+----------+
|    15088 |
+----------+

mysql> desc gif_stash;
+------------+---------------+------+-----+-------------------+----------------+
| Field      | Type          | Null | Key | Default           | Extra          |
+------------+---------------+------+-----+-------------------+----------------+
| content_id | int(11)       | NO   | PRI | NULL              | auto_increment |
| user_id    | int(11)       | NO   |     | NULL              |                |
| url        | varchar(766)  | YES  |     | NULL              |                |
| period     | int(11)       | NO   | MUL | NULL              |                |
| title      | varchar(766)  | YES  | UNI | NULL              |                |
| source     | varchar(1000) | YES  |     | NULL              |                |
| createdon  | timestamp     | NO   | MUL | CURRENT_TIMESTAMP |                |
| gif_size   | int(11)       | YES  |     | 0                 |                |
| mp4_size   | int(11)       | YES  |     | 0                 |                |
| webm_size  | int(11)       | YES  |     | 0                 |                |
| frame_rate | int(11)       | YES  |     | 0                 |                |
| num_frames | int(11)       | YES  |     | 0                 |                |
| label      | varchar(200)  | YES  |     |                   |                |
| width      | int(11)       | YES  | MUL | 0                 |                |
| height     | int(11)       | YES  |     | 0                 |                |

mysql> select count(*) from  gif_user;
+----------+
| count(*) |
+----------+
|   201022 |

SELECT url, title, url, content_id, user_id, period as cnt, label, width, height FROM gif_stash
             WHERE content_id not in (SELECT gif_id FROM gif_user WHERE user_cookie = '80.112.249.196')
             ORDER BY period DESC LIMIT 550,50