Post Lockdown protects your site-critical pages and posts by disabling all non-admin users’ ability to trash or delete them. It can also lock pages and posts, which will disable editing of the post as well as disabling trashing/deleting.
The plugin adds a new options page under the Settings menu in your WordPress admin panel which allows you to quickly search and select for all pages and posts of any post type. When you find the item you want to select, simply click it to move it to the right box and click Save Changes.
See the screenshots for an example of what an Editor would see when they view a list of posts with some locked and protected.