SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83c9b1d75c343dd8c11aa3b75740f2a0644aed3dc99ccafd2492a3cf35079c31' 
  AND token = 'l8NJbCmY4I0/f7DpSenK6oQhGsuWh3ZBN+F6jrXLcg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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