SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '4b1e1b0572c2821d1305036c200b7bfc4e2a554dcef680f2135568b3d1182fd5' 
  AND token = 'GxvzZaSlGQPVCpOZ/5N8UZDZYAWwF6M58TZTzvFHQ9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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