SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bc1865f8819d7f7703a3015c0224c9be862b31b0f11bcd0133448e8870aebb4' 
  AND token = 'MYrN9yScDPN7zT/zP03O0QfuqM1LGci8+LzngpCoV1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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