SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8169ce10b924e6d07ee780ada675ea928baffe2f15906faf062253520ab3d9f8' 
  AND token = 'CKMQe5lkF8BnokEo+QE5HrmwKRXvk1FjQcywsZ+k2II=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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