Kentico MVC 12 does not support viewing cached items like it did with the portal engine in previous versions. This is due to the seperation of the admin tool into one Application Pool (with its own memory space) and the live site into a second Application Pool (with a different memory space). If you are looking for something that is close the MVPs have an extension package that shows at least the SQL cached items: https://www.mcbeev.com/kenticocachedoctor-2-0-now-with-kentico-glimpse
Kentico Xperience 13 does fix this situation as long as you have a recent refresh installed.