SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccaecb68ea8cd1a7ece75a542303a739db108f42ddd3c2ca6003ce681bd1608f' 
  AND token = 'mvQtrSabS1A4xKpwzIC9ATyRkjXcWgxoxok/T+qqb30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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