SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35d786bbbcc4f8d2f7b7aaf30547e1ae2713b93334bde27e91b996c9ead5f674' 
  AND token = 'KFyyK7apLNZJ5wlLX4MXNmsLRmyYl3OxxiiEdtXDBkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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