The way I do it is quite easy, but also secure.
I have a text file with all my keys/passwords on my local computer, in a protected directory.

Using 7zip, I create a password-protected zipfile. This password is really strong, no chance someone accidentally figures it out.

I have a copy of this file on google drive (synced with my pc and in the cloud), and a copy in my mail, in concepts.

When you use an incognito window it will not store your passwords/keys, it will require you to enter all information every time.