SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '37c2ca15cc0eef2002ed27292d3d91edb3e8b384285e9b405747705324845476' 
  AND token = 'JzHXgbKIrBHmJmKZKImacDZH6NGPir07CKUDOysW6/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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