SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '89a6be4d4496b3b8f4ad11c377c664402161d313d87540f9023c0e52a3245721' 
  AND token = '/dbW0RHnWBMgkF6UmXmw6gFlfYMnHc7lcfHtTlqfbYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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