SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1180f49cf0600cb15a6be1a9eb82a8bf8e65e5b4789299fc7257fbe511df02fb' 
  AND token = 'DKz6/EVznNRu8N9hSk7AklUY76bljVvW+rAHHcEX8CA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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