SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0835011f7c625ad04bfc5185571556431a9dae0ecca2d15d20702eb60f9aa3b1' 
  AND token = 'r+4Kd8ZxUMllrczY/pfiqWZAuGku5WpEHbdJU9u263w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}