Seat belt warning fuse

No, there's no fuse for just the seatbelt chime. That would be stupid. Whatever fuse it's on is shared with many other things - probably dashboard lights or something mildly useful like that.

However, there is a setting you can use to disable it by using a scan tool or by going to the dealer and asking them to change it. Search the forums if you need directions on how to do it yourself, if you have a scan tool (like the ScanGauge).

There's also a switch that turns it off. It's a little bit hard to reach, but Toyota has a metal tool that you can use to depress it, deactivating the chime. You can find this tool near your elbow, attached to a retaining strap. After you get into the car, simply pull the tool from its storage location across your body towards the switch location. It's located inside a little box with a slot in the top, which sits right next to your hip. I'll never know why they put the tool so far away from the slot, it doesn't make any sense! Anyway, you'll know when you've hit the button - there's a nice audible click. To avoid the beeping, you'll need to use the tool to press the button right away when you turn on the car, and don't remove the tool until you turn the car off, or else the beeping might return.