Well, it’s not going to explode because it already has…

But if it’s really so old that it’s lead you should be careful. Is it an antique clock where it has value sentimental or other? If not just toss it.

The mechanism is pretty standard, so if you really want to salvage it, you can replace that (and keep the same hands) but definitely mask up and take it outside to clean the corrosion off. If it’s an antique then this has already happened at least once.