SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '393fc4933c7fbb6a957eadaf2a44bbc0641d4a779239c49e12b57e8bba2a9f47' 
  AND token = 'lRkH/XGMw7aeMS7QYnC+M+VUvyoppee81b5gWEihzYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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