SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bd10cd3f1f3e890290ca70814c8e7be3d21d5840cfea66d72bb87d6bfcfdf3a9' 
  AND token = '91nYphqhWpngz4diw8MhOzKsQDt9O7P2JHoLEHHWfTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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