SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4baa1519749df355434eb8e3cc257190adcc57cd0d36d1cb71159f1f3f61d25f' 
  AND token = 'GfcyneG3FA1WAtFuOyoQoh+4UDMQE9nMUdyD/Os3UZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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