How to get keyboard shortcut for downloads folder work again after deleting downloads folder?
⌥+⌘+L is the default key but if it is not working, I would suggest you create a new service in Automator. 


Set the dropdowns to Service receives to no input, in any application, or limit it to just the Finder if you like.
Add the "Run Shell Script" item, and set the content to open ~/Downloads
Save the Service, name it whatever you like.
In the keyboard shortcuts preference pane, select "Services" from the source list. 


Find the service you created at the bottom of the list on the right, and give it whatever shortcut you'd like. I hope this will help you.