SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '87e9f10ab42801aad17d840b5e03f1495e5f67d8505c0d5caa7eff97039f73c7' 
  AND token = '8zrq4Oya/eJZlnNsrYlsZxZw9/Kk5ykUxxIiuLwaHJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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