SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '857992b11cc66c999acda140e39291cbc181a588030333414ffb4e7d195b022b' 
  AND token = '2xaaeyA80Iz7dX42WsawLkLDoC+kJTM3Mb9XqfGsFVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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