I would recommend neither. But of the two, McAfee I would regard as simply unnecessary, while Clean Master I would classify as unwanted and possibly malicious.
Frankly as long as you only install apps from reputable sites (e.g. Play Store), and pay a little attention to what you are installing (check the permissions the app requests are reasonable for what it does, for example), you don't need security software. There are no "viruses" for Android, in the correct sense of self-propagating malware, so the malware that exists relies on tricking you into installing it. If you take a little care you are unlikely to ever have a problem.
But if you want some peace of mind, you could install MalwareBytes and just scan the device every now and then. If McAfee can be set to just scan apps when installed rather than being continuously active that might also give you some reassurance without the overhead of constant scanning, but I certainly wouldn't have one scanning continuously or checking each app every time I open it.