SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd8229545b9dad23c88341a39900893ff66871a909bf1fcb49c97a4f3b79fc328' 
  AND token = 'Ig0B+fbRwWmEwIAeQnpQCgkd/WVyJgkwOTvTwY5xEKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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