How to disable or 404 a single page view of a custom page type of a theme in wordpress?

Question

In my theme there are custom page types like "team". I do not want a public access to e.g. www.xyz.com/team/ or www.xyz.com/team/xyz

In both cases it "should" return a 404 error. How can this be done manually in Wordpress without using a plugin and if not possible manually then which plugin do you recommend?

I know there are plugins which can do this but they down the speed of my website too.

Answer 1

Oh so this technique would be the best one to use. Great. Thanks for the help.