SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e4db747bd4defba84baa58cb4b30c3c47427083dee96b38dacc1cbdc67e5f0f' 
  AND token = 'RrXcHIHuTrINMDUavupMtKOkxnugk+pIBbI7cY0CQE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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