Heat the olive oil in a large saucepan over medium heat. Add the chopped onion, carrot, and celery. Sauté for about 5 minutes until the vegetables are soft.
Add the minced garlic and cook for another minute until fragrant.
Stir in the bay leaf, dried thyme, and cayenne pepper, and cook for an additional minute.
Pour in the seafood stock and bring the mixture to a boil. Reduce the heat and let it simmer for 20 minutes.
Remove the bay leaf from the soup. Using an immersion blender, puree the soup until smooth.
Return the pureed soup to the pot. Stir in the heavy cream, cooked crab meat, and cooked shrimp. Heat the bisque gently over medium heat until warmed through, about 5 minutes. Do not let it boil.
Season with salt and black pepper to taste. Adjust the cayenne pepper for additional heat if desired.
Serve the bisque hot, garnished with chopped parsley and with lemon wedges on the side.