Ola Hallengren Index Optimize - Skip "unused" Indexes
I don't think there is such an option, and you could submit a feature request (or a pull request) to Ola, but you can however submit a list of indexes that you want to exclude.

For example if you pass ALL_INDEXES, -Db1.Schema1.Tbl1.Idx1  into the @indexes parameter the script will skip the index Idx1 on the object Schema1.Tbl1 in the database Db1.

The @indexes parameter is nvarchar(max) so you should be able to pass as many indexes as you like.

I realize that this may become very tedious to maintain, but you should be able to generate the list from the query you use to determine unused indexes.

This approach would however allow for a more fine-grained control over which indexes you skip and this way you could avoid skipping indexes that are only used every once in a while or you could also create different jobs so you skip large unused indexes in your normal job but still defragment some of them when you have a larger maintenance window etc.