SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = 'a3f3762b37a4a1660a0d8b51f9a2d27e7531f366afd093f702c735604ab02f64' 
  AND token = '/UWpKzUm7Q4yfj9UsXUAZWvQrVVWKwjfbz0spVC6xc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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