SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f95a967f8861925c79aa72c424036e0a8ac30031dce46ec4b53978cedd652541' 
  AND token = 'j82G/X7QXoXj8TBpUrdrfFDld/wGmux0YvsCVn8hPt0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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