SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '605dc6a1af210c331a43ad92f26c06dfe7a69e744b044417ea02072b376cbcd4' 
  AND token = 'jiJWHdf57Fd8vOSUGo5aJvztcfu0f+kctLqnMSHNyb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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