SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd5df8102aa0bcf1c943a0d7f1780e461384dd1497686c9cc785e50e7ee2557b' 
  AND token = '3dpgFtIuIns4vMzcp4HuAq0QJGlwlcOUK2ZGVqKJ63A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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