SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4697201fa2272501e23668429c283bcbc7cb132c65ab4175f7877526467d67f' 
  AND token = '9wXvBKLgDjrJTQYhvu3l9j6hPQ+xIsWPrMoILbkskYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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