SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '653786ca85b314f24d4eaba2a5143021afa399bc0714286860c9f16e6fd27d37' 
  AND token = 's5zopqO364YyWzHwtKumteThiaVKh9pByVgB1qizdXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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