We propose a decentralized access control scheme for interference management in D2D (device-to-device) underlaid cellular networks. Our method combines SIR-aware link activation with cellular exclusion regions in a case where D2D links opportunistically access the licensed cellular spectrum. Analytical expressions and tight approximations for the coverage probabilities of cellular and D2D links are derived. We characterize the impact of the guard zone radius and the SIR threshold on the D2D area spectral efficiency and cellular coverage. A tractable approach was proposed in order to find the SIR threshold and guard zone radius, which maximize the area spectral efficiency of the D2D communication while ensuring sufficient coverage probability for cellular uplink users. Simulations validate the accuracy of our analytical results and show the performance gain of our proposed scheme compared to existing state-of-the-art solutions.