This is the link for that asset in asset store
"Once you have purchased an asset from the store, it becomes yours to do with as you like within your games and apps. You will be able to use them in your game for commercial use with no extra payments.
You can also use free assets in your game for commercial use. Using selected (non-restricted) Unity assets is fine, though be aware that many developers use Unity to create their games and most are aware of the assets we provide."