SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f3d57748d92a6d30ec26175b85a873ddb07fd42850596c67949c385b4b92e46' 
  AND token = 'Fre+rmZSpMJ1/4L/A149HuCkzBv5XiYhdJVK5+XxoZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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