SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e6503cb4347f9f86595b20aaf6451d607a791611bbb2509e4346cbd5ceb7117' 
  AND token = 'QGpsytbtiYOr6qbExZ74rYpQIcJljeO0YG6zC3t+mRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00093

JSON explain

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