SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54cf1b9f85872c7734d68601ed23cf8a167c1d7e42e6defaeb8ad12d8742450f' 
  AND token = 'tDQ+HB9tZHYx1/DA8R9wOovYgKn9uOq7q+FFcCdjDiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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