SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df091f63ebf5b1b814df8d99a1cea4ec1ab39f2a0360725eb3ea9f78091baca0' 
  AND token = 'UfP0cE83DMQkaXAlhhjcIHDCdYBUzI+ItF/jSaiEzmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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