SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b57261387464a0f4844dadae614c2569c1cc1d9f5bf7f10dbcdac42370a02581' 
  AND token = 'AqGdrDViofuRcZ2uGTOArkC+YjN74NKhvItk+xN14GU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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