SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '590628543c9d7677672920510387a30d6bf2623435116104fde64c87e79b86e5' 
  AND token = 'YCSy/Yhe1xTG1KJqqh4HugYykLzY3+h7YtcM74ZOD+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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