SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31370f9ff9aecb601a97e8e3d41f201b5f97b817d91aa858908caa651b7f4bbc' 
  AND token = 'lioGfJJvsBErp8rao63XEhjQMkiGr5Is/ZvQ2riIOuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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