Heat olive oil in a large saucepan over medium-high heat. Add onion, celery, and carrot; cook and stir until onion is translucent and celery and carrot are crisp-tender, 3 to 5 minutes. Stir in garlic, paprika, and red pepper flakes; cook until fragrant, about 1 minute.
Pour chicken broth, water, and quinoa into the saucepan. Bring to a simmer; reduce heat to medium-low, cover, and cook until quinoa is tender, about 20 minutes.
Stir in diced tomatoes with juice, black beans, and corn. Bring back to a simmer and cook, uncovered, until black beans are heated through, about 5 minutes. Season with salt and pepper.