But it seems that all algorithms I found are prototypes and they weren't used in real applications.
Quantum computers do not exist even in prototypes
When they will appear in prototypes it will be too late for us to seek a reliable solution. And it's possible that when it will happen we won't know about it for some time. There is good website about it:
https://pqcrypto.orgI'm asking about algorithm which is good for today purposes and could be good for post quantum era theoretically. And it should be already implemented in code of course.