SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '40ff131365a5f1e38a61d692a383142fb16b7fca0fe38d7c19a329e462c16f2c' 
  AND token = 'AFbqiBQcHhipSjok+lxBVT+HozzTv5GzVM9Wf+vmqDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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