Is it possible to fetch a single item from a list (not the current list or item) without making an HTTP service call. If not, then why? Don't you think it should be something readily available. I can see an action that allows you to update a list item, then why not something as simple as retrieving an item?
The question is what do you really need? Getting an item does you no good, unless you want information from the item, or want to change the item. You found how to change an item. To get fields from an item, you would use the lookup and select whichever list you'd like, which field from that list, and the "WHERE" clause, so to speak. You can only specify one field so you can't, for example, find the item where the Title is "My Title" and the Created Date is 4/13/2016. Additionally, if there are multiple items that match, it will return only the first item it finds that matches.