Heat a saucepan over medium heat. Add coconut oil, lemongrass, green curry paste, garlic, ginger, and red pepper flakes. Cook until fragrant, about 2 minutes.
Add broth and water to the saucepan with the lemongrass mixture and bring to a boil. Add spiralized zucchini noodles, mushrooms, snow peas, bok choy, scallions, and lime juice. Cook until tender, about 4 minutes.
Season soup with salt and pepper. Add cilantro. Stir to combine, adjust seasoning if needed, and ladle into bowls.