SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bf7177286f846506f71a4401da89323824b45c363c89632b09864ac462fedda' 
  AND token = 'BkL4vEf8xdjd6XmfZzqUFXgroeMmeE8SfBctd2Yt82g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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