Twitter's advanced search does not support such an option, but you can try some 3rd party like:
You can also use Twitter's API console tool by authenticating through Twitter in the browser and providing your handle and userid.
The last resort would be to use Twitter directly:
- type the name of the user whose favourites you want to see into the top search box. If you want to view your own favourites, click the Favorites link on the right side of the screen and jump to the last step
- click the user's name on the right side of the screen under People results
- open the Favorites tab which will display all tweets the user has made a favourite
- press CTRL + F and type in a keyword to search the favourites on that page (if a match is found, the favourite will be highlighted)