That is a great point – an exact match would be a good addition.
For the moment you could select a row that contains a zero and control-click (right-click).
What ever you are clicking on you will see this option….
Then only those rows are selected …
Now when you open Data > Find & Replace only the rows with ‘0’ are shown.
That said we agree having more options in the Find and Replace would make sense, rather than always having to preselect.