All of Jesus’ recorded prayers in public were short. When alone with God, he could spend the whole night in communion with God.
My experience is that those who pray most in their closets generally make short prayers in public. Long prayers are too often not prayers and they weary people. How short the publican’s prayer was: “God, be merciful to be me a sinner” (Luke 18:13). The prayer of the thief on the cross was a short one: “Lord, remember me when I come into the Kingdom” (Luke 23:42). Peter’s prayer was “Lord, save me!” (Matthew 14:30).
If you go through the Scriptures you will find that the prayers that brought immediate answers were generally brief.