SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd91459954f3e72b33782438a2c0baa6363d8ed308bc2db442e19dba2ef83e0d7' 
  AND token = 'oGIg6CDRjL2pvnekZYJb2pVzuJWOwBT9u60RsBjjAKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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