Delete data from history

[jungleslow]

Hello,
I tried to delete data on history_uint with :

DELETE history_uint.* FROM history_uint LEFT JOIN items ON history_uint.itemid = items.itemid WHERE items.itemid IS NULL ;

I was waiting.. And then after two hours I lost the connexion.
So I tried to launch again the MySQL request but now I have an error :

ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction

I changed in my.cnf the timeout to 500 :

innodb_lock_wait_timeout = 500

But still the same error after 500 seconds :/

select count(itemid) from history_uint where itemid=34321;
+---------------+
| count(itemid) |
+---------------+
|        125743 |
+---------------+
1 row in set (6 min 30.41 sec)

mysql> delete from history_uint where itemid=34321;
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
mysql> select count(itemid) from history_uint where itemid=34321;
+---------------+
| count(itemid) |
+---------------+
|        125743 |
+---------------+
1 row in set (4 min 41.07 sec)

Can you tell me how to fix this please ?
Thanks !