First, check your spam or junk email folders. Make sure that you are checking the email account that you used to complete the purchase. Also, please make sure you white-list all emails from the domain 'mindsightstudios.com' to be sure that you will receive all your license information emails.
If you are unable to find your key, click here to have it resent.
If you purchased from a reseller, please contact them to receive your license information.