Smart applications came into existence with technological advancements like Software Defined Networks (SDN), Cloud computing, Network Function Virtualization (NFV), and the Internet of Things (IoT). Internet of Vehicles (IoV) is a highly dynamic application with limited tolerance to latency since a small delay can lead to drastic disasters. For efficient network and vehicle management clusters are formed in IoV. Secure key management is unavoidable to secure communication between the vehicles in the cluster. In this article, a sustainable cluster key management approach is proposed to handle the dynamic and latency-sensitive nature of IoV. Security analysis proves that the proposed approach holds secrecy in group key management. The proposed approach reduces the communication complexity to a single broadcast for re-keying. The analysis proves that the computation and storage complexity is also minimal, hence proving that the scheme is sustainable with limited resource usage and efficient for usage in latency-sensitive IoV environments.