Yes, you can use phpMyAdmin with your hosting account.
You can access phpMyAdmin for your account under My Services → WordPress Hosting (1), then select Service Management. From the following menu, select the Databases (2) tab on the left-hand side of your WPX admin panel:
You can access your phpMyAdmin by clicking the similarly-named button (3) over on the right-hand side.
If you get stuck with anything discussed on this page, please contact WPX Support via live chat (use the bottom right hand widget!) and we will usually respond and help within 30 seconds.