SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b97085c422d3e1a607a8c696e3cf0ce9dfd346b8857a39228ed24e496a541ae' 
  AND token = 'PZKlFWF/JQjJXO442uyW/a9UDzL3sZ0BIMVEoMHjYdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}