Explore tool should be in the top-most menu of ArcGIS Pro
It is very inconvenient to select Navigate tool in ArcGIS Pro. It is placed in the MAP tab under Navigate group:
Thus, for instance, then I have to navigate in a 3D scene while editing it, I need to repeatedly go back to the MAP tab to select Navigate tool. I think, this tool should be moved to the top-most menu (near Save project button).
The shortcut is a good option, but you can also just add the Explore tool (or any other tool that you want all the time regardless of the view you're in) to the Quick Access Toolbar by right-clicking > Add to Quick Access Toolbar.
You don't have to move back and forth between the ribbon or Quick Access Toolbar to switch back to the Explore tool. Like others have pointed out, my preferred method is to just press the scroll wheel usually just to pan while I have another tool activated. If you want to switch to the Explore tool, when you have another tool active, just right-click and bring it up from the context menu.
In fact, I just demo'd this in the ArcGIS Pro Tips and Tricks session yesterday at the Esri 2018 User Conference. If you happen to be at the User Conference, check out ArcGIS Pro at the 2018 Esri User Conference for more sessions!
Thanks for the demo, that illustrates it well. I didn't mention it but there's also a great demo in the documentation for the Navigator. I left it as an Easter egg for enquiring minds. 
I'd go a step further and say there should be keyboard shortcut for this, e.g. ESC stop drawing, halts your process and returns your active tool back to explore/navigate.
When I came across this the other day I was dumbfounded that to be able to move my map while using a tool I had to google search, come back through this forum then modify Pro so that I could do a basic action that has been a part of Desktop (and every GIS application) for decades.