Scale it to the size you like in your slicer such as Cura. You can enlarge it to be wall art too. If you have suggestions on other keychain ideas let me know in the comment section. I can make a STL file in a post like this so you and others can print them. Feel free to "follow me" to see the other designs I come up with.
For added detail you can use model paint and accent the raised text or the recessed areas like: