The entire Declaration of Independence is saturated with Enlightenment-era ideas and influences, the most noticeable and famous of which stem from John Locke. It can itself be labeled a product of the Enlightenment and an illustration of Enlightenment-era political thought.
Like Locke, the leaders of the American Revolution envisioned politics as fundamentally contractual, being based on a contract between the rulers and the ruled. This tradition of political theory, known as social contract theory, was one of the most famous strands of political thought associated with the Enlightenment, one which stretches outside of Locke to also embrace the absolutist Hobbes (who predated Locke), as well as the later Rousseau. The entire argument sketched out in the Declaration of Independence is contractual at its core, stating that Great Britain has failed to uphold its obligations to the colonies, and therefore the colonies have a legitimate claim to independence. Note how the entire Declaration of Independence is almost structured like a court case: after setting the basic logic and argumentation, it presents a series of very specific grievances, the aim of which is to prove the claim that the original contract has been broken.
In addition, where Locke's influence is particularly strong lies in his vision of what that original social contract entails. Ultimately, social contract theory has involved imagining what human existence looks like in the absence of functioning society and governance. From there, one can then extrapolate the original social contract that would have given rise to governance to begin with. For Hobbes, the state of nature was a state of lawless brutality (from which he constructed his absolutist vision of the social contract), but Locke defined it first and foremost as a state of freedom that is fundamentally rational but also deeply fragile, with the potential for violence.
For Locke, thus, people surrender to governments and society some of that boundless freedom to protect those freedoms that are most foundational to living and enjoying life: for Locke, they were life, liberty and property. This same vision can be applied to the Declaration of Independence, which argues that government, likewise, was founded for the purpose of defending the natural rights to "Life, Liberty and the pursuit of Happiness."
Finally, both the Declaration of Independence and these larger currents of Enlightenment thought were deeply concerned with the problem of tyranny. One can look towards Montesquieu and his differentiation between legitimate monarchy and despotism, a differentiation that ultimately boils down to the rule of law. For Montesquieu, absolutist kings (as powerful as they were), still ruled according to traditions and customs, as opposed to despots who (so Montesquieu claimed) ultimately ruled according to their whims.
To this, one can also refer to the ideas of the resistance theorists (Locke among them) and their own concerns about abuse of power and the breaking of the social contract. "Tyrant" would have been a powerful and politically charged word in an Enlightenment context, and it is not by accident that the word is invoked in the Declaration of Independence. It is not simply that the social contract has been broken, but the monarch is explicitly being charged with acting tyrannically, a claim that held power within the intellectual and emotional climate that shaped the Declaration of Independence.