Wash and slice your cucumbers into thin rounds. Dice the red onion finely. Chop the cilantro coarsely. In a large mixing bowl, combine the cucumbers, corn, red onion, and cilantro.

In a separate bowl, whisk together mayonnaise, lime juice, chili powder, ground cumin, and garlic powder. Season with salt and black pepper to taste until smooth.

Pour the dressing over the cucumber mixture and gently toss to coat all the ingredients.

Cover with plastic wrap and chill in the refrigerator for about 15 to 20 minutes.

Stir the salad before serving and sprinkle with Tajín or extra chili powder if desired. Serve chilled.