If you run a Magento backend website and you get an error such as this:
“Access is locked. Please try again in a few minutes.”
Here is the solution to your problem. FTP into your /public_html/var folder
and then edit this file
One you open the file you should edit this line:
Brute-force-bad-attempts-count = 0 (change whatever number that is in place of the zero to zero)
And then save and clear the cache on your Magento backend and re-login again.