SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '211985f5fd67b1f62437345f42f7ba2395ca069c242560eafd4caed07b5eb4da' 
  AND token = 'Btqa++/U2YQ5Eh1Z9legZ8ZFgoDPUCVXJG5lTvhqUeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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