SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c729889a10f0902517c8754cdb03d7ecf109f048a653ee688e1141ab2a99738d' 
  AND token = 'ODyzut9NzJSBojgmsznDoS+FqYYlprxunAI9ZQI25HM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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