SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f55e1f9a6218c73c413141d1cde9689e97847c9306a9c869b8ace31f3a7eb50' 
  AND token = 'ZZBhGOK7esx1YNBPJxn9ZeBYi4UpLVPYFP25SgZhGzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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