SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0d7df2d0e7326fba4ec7d969ed3320990d9361734107e2924ef6d5b5fd35628a' 
  AND token = 'poGNTTpjXUYuCvO4zYjXZNDxNOx1fbaaS07MzKMkNgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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