SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f8f86dd3002cd182e0ed848e7aaa84e18118082a2995518876d65ccf4839049' 
  AND token = 'TRe9TZd4yg3wK1CXiax5pXfP2FHhWkA/Dvh4xMSdZPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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