SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '30fdf6c3ccbb42510c833ec7abfdb6d6bddd2fc63e8d7b3bf88757d0059d0341' 
  AND token = 'gWMpGI14DUuYrhk+rBrlPtbTNEUwzPW/YLsWgQQFnnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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