You can safely (Uninstall) MSS+ through your Control Panel. Evidently you installed it with another program via being "Bundled". Most likely scenarios being when updating Adobe Flash Player. There are other programs offered similarly as well, Ask Tool-Bar, Norton Safe Search, etc.
Just remember in the future to untick the (Optional) offers. McAfee Security Scan Plus has no (Protection Capabilities).
I have both McAfee Total Protection vs McAfee Security Scan Plus. on my computer. Is this a conflict?
Is this a conflict?
Not really but Security Scan Plus is totally unnecessary and should be uninstalled in the normal manner via Control Panel > Programs and Features.
It merely scans and tells you if security is compromised and then would suggest a McAfee product. It comes usually as an optional download with Adobe products so always watch out for that box that can be unchecked whenever you are installing anything. 3rd party optional software is quite common now as a means of keeping costs down by using cross-advertising.