SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d8d2b43b5a1da17d58c8adcd71505f44583bc02da3cbe21083ff6cbb74b7853' 
  AND token = 'EvQFrkuAK/kRz7NN6vZoqRKkDpvxYznxtIj0jIwP7e4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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