SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2dfd69133c538371bb235092855af10d2407dc8fec7f4a211bde3018bdc45f70' 
  AND token = '7DF8ZqFmaMvBorEtepGIa+mIPU++todkY4bm91HQ9t8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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