SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9dabe5761569cd7be5cbc5fad892f5944d70c35816a30e4f3422cbd4f607af44' 
  AND token = 'wrFYQbwtoEztJ8WsW2F2UnLphr77fNU2NFixy9FOITo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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