SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4824aeacc3559b464ab3dd64fd9af77b42dc69d41353dd659bc06e3852a4bf2d' 
  AND token = 'wwa5vzAv/Qf/+abvIJDlAqG21eBlf//3WRaXgyWHnG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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