SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2576b1d0e8a91f560b3d5e29acf1dfd83ffed132609ed0bd7b28862d04e5e13f' 
  AND token = 'PmwQh4CJ8ZxCzFUcC5UzRVLMGMs0jSaphnjMHNO/Shw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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