SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ef3de88d07f3c4f55e2112cb301674f308683a8a30157971954b7d25626dfa33' 
  AND token = 'M5uzAtVUQDQZCPLfUdc29CIwR8jbF0YOLvNgiODi88E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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