I'm going to second the ffmpeg answers, they do the job but won't be completely accurate to timestamps due to cutting at key frames. That's how you persevere original quality though, and it's fastest.
If you need to reencode to fit a target size as well, there exists tools for that too. I made my own for cutting shadowplay recordings by selecting start and stop points in the video and encoding them to fit the discord 8MB limit back in the day. My version is not exactly user friendly to get going though, and not updated for the last 5 years or so. Should still work though.