Is there a way to lock certain pages from being edited by anyone other then the admin?

Have a look at the Members Plugin by Justin Tadlock.

It has a “content permissions” feature, that let’s you restrict posts and pages by user role.

Alternatively, if you wanted to implement this yourself, you could write a shortcode that redirects the user conditionally. And place that on pages you want to restrict.

Since there is an excellent and well written plugin for this job however, this is one of the few occasions where I’d recommend using an existing plugin over coding it yourself.