It's hard to find new 5v tht(trough hole) fuses, most that you will find are smd (surface mounted and not with legs). That's why you should get it from another board, to keep it in specs. Using one that is rated for a higher voltage will work but the over-voltage protection is gone also.

So I searched, and I wasn't able to find any motherboard that had a keyboard fuse. Even the older AT ones. What should I do?