SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd705d25f9a94a683d969ee949f48410a7e7a83a77fae67bee0fd775f6d393d4c' 
  AND token = 'OpdWfNgQQbidh0XpfO7vK/BHVNSykswkn8FwRp2v9Fs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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