SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ba035c06f98732f71bcf64395923a50717c518459ae793039da36c442aa9a295' 
  AND token = 'a5GkTOYgkf4EZ/03vTIpfZGJB5vI0Jkuj6WAcWNQnzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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