SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5234a93b04f7070cf4f6efed0ee06782dff1ddacecc310ca35207d9c08b9d14b' 
  AND token = 'Y1E1TW4yZLIpI5R4c4qwHy2VBXyJQBct0GXaHuKznjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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