SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8e16bdefd726a5075d98997a35174326d15d80e3842d35283ca2aef1cba3e76f' 
  AND token = 'WXYVudjq+PlT0dmzeERVOUZ0+JgGG234PL8Ks45FTNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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