SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3ce40bb5dbcc17961a47fdc9b7f4fdccf5a345e8b93a6547e9871f1158100321' 
  AND token = 'u5LavoEWcZF9CLTor8g9JmgxRmJUsHDcJ4KAuVLKP/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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