SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09f6ec02eda560b27a8161bac25e2f781a49942359b407b65ccb7e4b105efd23' 
  AND token = 'Pw0mlJFtsEhO0Nrwk+lWZq6hLoSGmSSPcdbFnKZlixU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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