You can download your licensed track immediately after you've completed the checkout process.
You will also find a link to download it again by logging-in to your Lickd account and visiting your My Account > Licenses section.
Your My Account area can be found by clicking account in the top right-hand corner:
Your "Licenses" area can then be found using the top-navigation links.
Here you will find a link to "Download audio" which will trigger the mp3 file to be downloaded to your device: