Sprinkle the gelatin over 1/2 cup of the tomato juice in a small bowl and let it stand for 5 minutes to soften.
Pour the remaining 1 1/2 cups tomato juice into a saucepan and warm over medium heat until it just begins to steam. Do not let it boil.
Stir the softened gelatin mixture into the warm tomato juice until fully dissolved. Remove the pan from heat.
Add the vodka, Worcestershire sauce, celery salt, hot sauce, and lemon juice. Stir well to combine.
Mix in the diced celery, then pour the mixture into a lightly oiled 4-cup mold or loaf pan.
Cover and refrigerate for at least 4 hours, or until the aspic is fully set and firm.
To serve, run a thin knife around the edge of the mold, dip the bottom briefly in warm water, and invert onto a plate. Arrange the halved cherry tomatoes and celery stalks around the unmolded aspic.