SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f79672b188f451937a36fefc3f7e9e4bef925ed86340806ca98b4b717871ad1e' 
  AND token = '9XzPoKWlsCJWnNI7WnEnjqdfOizoKh3B8TxYXgGhVoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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