SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4135f839d6e4e9d424b3bbcf9e7adac8096c71b3b2a1ae82f1c0f970ef00ac7e' 
  AND token = '8dwwBENmxHq20rDh6YA15wleGYboJdlf5SXqinKMwgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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