In a small bowl, combine salt, black pepper, smoked paprika, garlic powder, onion powder, and dried thyme.
Pat the chicken thighs dry with paper towels and season both sides evenly with the spice mixture.
In a large skillet, heat olive oil over medium-high heat. Add the chicken thighs and sear for 2-3 minutes on each side until golden brown. Remove from heat.
Place the sliced onion and minced garlic at the bottom of the slow cooker.
Arrange the seared chicken thighs on top of the onions and garlic in the slow cooker.
In a separate bowl, whisk together chicken broth, soy sauce, and honey until well combined.
Pour the sauce mixture evenly over the chicken thighs in the slow cooker.
Cover and cook on low for 4 hours, or until the chicken is tender and cooked through (internal temperature should reach 165°F / 74°C).
Once cooked, remove the chicken thighs from the slow cooker and let rest for 5 minutes before serving.
Optional: Spoon some of the cooking juices over the chicken when serving for extra flavor.