SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec3c74dd05a27df96be92fc744dc8b8ea58341182ae2650f60b7d58d9e7fe54f' 
  AND token = '3ChFMNHGNxKvDxS1FhV4jwVMEj7TvrByqYMkfakKALM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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