SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff3be941d097fe209b2f5e979a4e77877fabe231bd4a627ae0b584fa8f039e80' 
  AND token = '9ausSG496bUz7V/PUF9ZoL6qDAo8aYsV85wt8r7fVLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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