SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd41dc5b5ca0a787e26f14bbe37d4f945284dcf38c4a2febec7f61a3694e8db6f' 
  AND token = 'cGlpsJtqid5fGLkvsceVgEjKUVAlsSaY/IYMHwxFCDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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