Currently I have to open Team Explorer and click on Source Control Explorer
as below snapshot.
I do this very often and need a hotkey for that.
What is it then?
Try with below step:
Go to Options of Tools menu
Select the Keyboard from Environment
Select View.TfsSourceControlExplorer from Show commands containing:. You can type View.TFS in the textbox to filter the list.
Enter your hotkey in Press shorcut keys => click on Assign
Hope it helps!