SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = 'ef66f633af47d883b6f70b9f7b4055af7b541bfb2fd988d37e721706f12c1f8b' 
  AND token = 'zaNpxmL3IC8VRLgzVMmHbH+vwMGZIh2qBjVWmSq0X88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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