SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5db5020642bf239c1556ae46ea8c1bb01bfc43b99b17e752f399db8319957484' 
  AND token = 'MsXPvv9vUjj/usFYFKDu8Wg3JbYyGFFxD5mtTzM96ak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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