6G networks promise advanced applications such as immersive extended reality, autonomous systems, and massive machine-type communications, all of which demand highly secure communication. Yet, the rise of quantum computing technologies poses significant challenges to classical cryptographic methods, creating an urgent need for security designs resistant to quantum attacks. Quantum key distribution (QKD) is a promising solution; however, its deployment is currently constrained by expensive point-to-point connections that require dedicated devices at both endpoints. These constraints, combined with a restricted operational range, have limited the use of QKD to niche applications. To address this, our study introduces a scalable microservice framework for SDN-enabled QKD networks, leveraging the SDN Controller and its support for diverse communication protocols, including REST APIs. Our findings demonstrate that integrating QKD within an SDN-enabled microservice architecture can enhance network performance and flexibility by improving scalability, reducing latency, and extending achievable secret key rates over longer distances.