As Canon has decided to obsolete old scanners among them are also CanoScan Lide 50 they are not providing drivers for Windows 10 anymore.
I managed to Google it and find unofficial drivers from here https://www.webwhitenoise.com/item/2009/05/canon-canoscan-lide-50-x64-drivers/
File name is called DNA Canon LiDE50 x64 Driver.7z
After installation story is yet not ended because you also need an app to use scanner. Original Canon CanoScan Toolbox was not working, it stopped with error "Cannot select TWAIN source". I tried several versions and failed to make them running. Free app called Scan which is available from Microsoft Store also is not working. Finally I managed to find NAPS2 software, and that works like a charm. You can download it from here https://www.naps2.com/
If you have difficulties with steps above you might need to enable Windows Test mode. Here is how it can be enabled/disabled https://www.howtogeek.com/167723/how-to-disable-driver-signature-verification-on-64-bit-windows-8.1-so-that-you-can-install-unsigned-drivers/
And maybe also this is needed http://www.damirscorner.com/blog/posts/20141215-InstallingCanoScanLide50ScannerOn64BitWindows81.html
In my case folder to add to PATH was C:\Windows\twain_32\CNQL60
