SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac1de161c52fb6f38973e856c056f5a1b4e9b4746d05529aef52a1d32095348f' 
  AND token = 'GSsNvVKJKjLXGKuDZ22yM27mwCagU5WPOk54sstJR4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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