SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe2900c25b0090e970956985fd8cee9e0434fdf8f5f695833aa54873e7d35f1f' 
  AND token = 'BXOOTtBOw2vhy2TgXrClAwTaW7hdrtDgoXYwQ/6QzcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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