Can you have a Minecraft account on two devices?

I currently have a Minecraft account on my iPad and would like to have this account with the worlds that have already been created on my Android phone, is that possible at all and if so, how?

Unfortunately, this is not possible because you have to differentiate between two operating systems. If both systems were iOS / Android, then that would be possible.

But that's not how it works. You will have to buy the game again.

But that works if you log in with my Microsoft account on both devices

Yes. To do this, however, you must first purchase the game in order to log into your account.