SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '82731e35837b229c467c57477c8130abbe0d2d6c49196608270b8a2f30fe3aa7' 
  AND token = '3lCWVklJ1Vsn/mfrCkB5WSUoFbUKv36GCC7DhIsSgHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00091

JSON explain

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