Whatever saying the others, since I got this experience, I suggest DO NOT install this plugin.
I am sorry, I did not see your inquiry until now when I searched my email for it (it landed in my spam mail). I will also reply to your email inquiry.
The time limit doesn't lock you out for "X" amount of time, tather it is: "How many failed attempts in X amount of minutes will block the account"
In your situation, you will need to use a different login to unblock the user, or if you don't have another login, you will need to change the value to 0 for the field "block" directly in the users table in your database.
Also, I have updated the description of this plugin, as it is NOT MAINTAINED and I will not be updating it.