SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58a8f2155cd4465b53fe387941fd36279a1350042b8fd010573cc3dd826e42d7' 
  AND token = 'Hgv3wsuamqnRkd6Xt9WZ3jmqZTKgWH8BXlvrP2PVDf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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