SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2bd44617d1f797134ad6a7ca3ae6a74096b87479c673cf58b331889e2c68ef1' 
  AND token = 'xXjhplyRci5INmJ4VIYwcPgi2SOxgNbGh5rw7O9SXq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}