SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6565c90595bbe36a97297540b9a03b581269e001e8f9e7b05e8c4c55183a207' 
  AND token = 'rK63hlbq7UzZdfCoIRNKrS3k2ffcPJrrhkjXTqk9FDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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