What's the timeout for mysql LOCK TABLES statement?

Can't find it anywhere.

I tried to set variable innodb\_lock\_wait\_timeout ini my.cnf but it seems it's related to another (row level) locking not to table locking.

Simply it has no effect for LOCK TABLES.

I want to set some low timeout value for case of deadlock, because if some operation will LOCK tables and something will go wrong, it will hang up the whole site!

Which is stupid for example in case of finishing purchase on your site.