SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae9efafac2288e46b8f4699875dce5970e74f39739eefabfb8836fd3e2a68847' 
  AND token = 'DHSUaiRcUo+lfaHOi4lJTcSTuV7DZjEZD6bS4kOUc5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}