Refer to the answer here.
Basically, rootness trumps permissions.
Permissions 000 means only root can read or write the file.
I'm not aware of any extra special use for the combination of root
ownership and 000 permissions.
Also, you could find some worthy information from this question as well.
So, as user Hauke Laging points out in his answer,
Always assume that
root (and any other user/process with
CAP_DAC_READ_SEARCH) can do everything
unless an LSM (SELinux, AppArmor or similar) prevents him from doing
That means also that you should assume that all your keystrokes can be
read. Passwords aren't really safe. If you want a serious level of
security then you must use a system which is completely controlled by
you (and not even used by anyone else.
So, even permissions 000 cannot restrict the root user from reading file contents unless there is any LSM preventing the root user from reading the file contents.