SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ddc00d31b34f0ed5ab623827555d99c69397df7cc67f6aa12a169c71af1928e2' 
  AND token = 'PT6uRWQYKx4dqZc80eHSpYtZOGzKxdet8wf8/yiYy2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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