SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eec7a55c967ee82259fb96332263e4527f647aee4b199b947be7fcd3fca697f8' 
  AND token = 'mq1GLH7MLXNY+vJdLZtu9zJVEb026N0U7ATc44zoNPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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