SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '524d3dc69154c16f006f5b60205e0ca36f0bfbb9308c0f994936c1231cd8105c' 
  AND token = '5akDhnQqNHqrpHXe2lMqgGfHHmDiMk9MH2uPUw5qdhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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