How to remove a music control from the lock screen that is not in the control center?

You could try a Force Restart of the device, it will not change any settings but might clear what’s behind the issue.

https://www.macworld.co.uk/how-to/iphone/how-restart-iphone-or-ipad-3662903/

If that doesn’t resolve or the issue reappears once you play music again you might have to try Restoring your device.

iCloud: Restore or set up your iOS device from iCloud

But it before you try the latter make sure you are upto date with respect to iOS which is currently 11.2.2 - to check go to Settings/General/About and look at “Version”.

ps. These links might help, appears it not the first time this has happened!

http://www.idownloadblog.com/2018/01/11/how-to-fix-stuck-music-player-widget-loc k-screen/

http://mobileinternist.com/remove-music-player-widget-ios-11

Force Restart is a bit like Rebooting your Mac when things start to go glitchy for no apparent reason, use it sparingly but it can be effective. If the issue was just something getting mixed up then all should be ok and you will not see it happen again, but if it's a deeper problem you might have to resort to some of the other "suggestions" contained in the links.