SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26e13d3aeee0cc1ec88a7709de0079e590f51a918138ac7b51b570a7d58de7a4' 
  AND token = 'hxXVGjSDYTlQlpEJjv8/fi4NS/l9tS9S/mok0VuDM9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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