SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47fbd47accabca19a63618955f0ce4449ab807efd737db42e14fd5d510098da0' 
  AND token = 'PzM1Ama6wOjTPAg2PuEyknbs8a2NBXVCqKJoBhXXQGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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