I'm quite fortunate to have access to a royalty free music library through my network, so I'm a little out of touch with where is good for this kind of thing. BUT what I use to use was the widely used Incompetech website (https://incompetech.com/) and a composer on YouTube known as teknoaxe (https://www.youtube.com/channel/UCtgf00GvfFQVsYBA7V7RwUw). Keep in mind, though, if you use any of the tracks from these two then you are meant (legally, though I'm sure a great many ignore it) to leave a credit for them in your video's description.
YouTube's list of copyright free music is a pretty good start, there is a lot of tracks to choose from and I am sure the mood and tempo you are looking for would be there, sure there is better libraries to choose from but some of them may require a purchase or license to use their libraries. Not sure if that is correct. I suppose I don't really mind at the moment as I have only 18 subscribers and most of my videos have less than 20 views