Preheat the air fryer to 400°F (200°C) for 5 minutes.
In a large bowl, combine the cornstarch, ground cumin, paprika, garlic powder, salt, black pepper, and red chili flakes (if using). Mix well.
Add the carrot sticks to the bowl with the seasoning mixture. Toss until the carrots are evenly coated with the seasoning mixture.
Lightly grease the air fryer basket with cooking spray or oil.
Arrange the seasoned carrot sticks in a single layer in the air fryer basket, making sure they're not overcrowded.
Cook the carrot sticks in the air fryer at 400°F (200°C) for 12-15 minutes, shaking the basket halfway through the cooking time to ensure even cooking. The carrot fries should be golden brown and crispy when done.
While the carrot fries are cooking, prepare the sauce. In a small bowl, mix together the plain non-fat yogurt and sugar-free ketchup until well combined. Adjust the consistency by adding more yogurt or ketchup as desired.
Once the carrot fries are done cooking, remove them from the air fryer basket and transfer them to a serving plate.
Serve the hot carrot fries with the yogurt-ketchup sauce on the side for dipping.