SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6714e0230d5e477504439a4d6cc4c0225c310fb819da563bf03edd756c231c5d' 
  AND token = 'hvpmGGZ8W+Lr3uQy9pg+PFnb8LNNxfrBZiNwAy4tNpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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