SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bb6d4573a6021d74e2f3b4d64e326e15cfd6d7f99b79da81768637596c488cc' 
  AND token = '93TjkxFJCcPsH67pxgtF1C4hnc6I5PqhGa5yad6dRWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00062

JSON explain

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