SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '676bcbacab558a26a114b6da7e9b95b0c5e262fafa2c198a34c7d3394ac50201' 
  AND token = 'zP+Bjm9Kw+8huCxQb0XDYjBBC41TaKxIcO2wwOlpuOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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