SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '08c19113bfbba91367b7ece899ed2f2c20b83398574fa98c561853829846ae70' 
  AND token = 'FNKE9xVby7M01QVY/WjCzBrMxGk2hc0vuhjDw5jyZtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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