SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27eb37c52a9f8bae6010afdd7c0ee258f8ca78b593871ebc1717f1d563a1b723' 
  AND token = 'Vmpc5YXsjKzM3WKNgt/fysGHSxqVzI9xt2+UZ0cxsCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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