Short answer
Yes. Press ⌃⇧⌘U in any app and Aktar uploads what's on your clipboard: a file you copied in Finder or an image such as a screenshot. The link is copied as soon as the upload finishes.
The shortcut works even when the menu bar panel is closed. You can change it to any combination, or clear it, under Settings → General → Keyboard shortcut: click the field to record a new shortcut or press Delete to remove it.
The shortcut uploads one item at a time. If you copied several files in Finder, the first one is uploaded; to upload many files at once, drop them on the panel instead.
While the panel is open, ⌘V does the same thing and ⌘, opens Settings. In the library window, ⌘F jumps to search.