Select some scouts, alt+right-click empty space, click auto explore.
You can change the keybindings for all that, naturally, but that's the default.
Auto-explore puts scouts into a mode where if they don't have an order they'll automatically pick a nearby planet you don't have scout intel on and go there. Once they're there they go somewhere else that doesn't have scout intel, etc. It was developed mainly for the don't-show-unexplored-planets option but it also works for scouting in a "revealed" galaxy with fog-of-war.
The new auto-picket option is for when you want to actually station a scout on the planets in question instead of get a flyby.
Neither is at all efficient about moving the scouts around in maximum-survivability stacks, etc, but they're not intended to be.