SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd4be3105b43fc35fe4ae6ea41cf4028c6cefe0750be8dae4dea471731b6d365' 
  AND token = 'FzuJYJfjQeRC9aO/ddX3tq7jok75GzUh2BWWuj2oZ/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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