SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b96f0bf998c0c557f7bde5eae3a27c8b6d07afc63356179c80d8f7fddfb2637' 
  AND token = 'lV78FUafiuDU/FifQPX19bQQvSMD/FILg/QnK8Vu4cs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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