When I run from flask.ext.mysql import MySQL I get the warning Importing flask.ext.mysql is deprecated, use flask_mysql instead.
So I inst
flask.ext.X is the old form to import a Flask extension, it is deprecated since Flask v0.10. The new way is to use flask_X. That's why you got the first warning.
But apparently, Flask-MySQL does not update it's name form and use the flaskext as the package name (chedck it on GitHub). That's why you got the second warning.