SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dabb16a104b057440cdd9ef9df21be0cc83393f85a3872121de8e0f86ab6444' 
  AND token = 'hJsjYBFzMqksaw16YSZErLxYbWO2tZ532UIHiK46kwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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