I have accidentally discarded my Hive keys time ago from my gmail drafts, and I was lucky enough to have Active Key saved in phone clipboard as I had copied it before so it was there and I took my Active Key from there.

That is indeed luck. But it is not really safe to copy it to the clipboard, nor storing it in a Gmail draft. The best is to backup your keys. Preferably on papers on a safe place. That cannot be hacked.