I have McAFEE live safe product and in my account settings it indicates that I have 354 days left, which is actually I have another product of the same type and double product keys in this case.
I wonder if it could be used now as additional time for the same product or must I wait for the first annual membership period ends ?
Is the other product key for the same product as well. If yes, you can go to https://mcafee.com/activate, use the product key and it would give you the option to add it to the existing product. If it is for a different product, I would suggest you to wait until the current product expires and then activate the second product key.