SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '83395d924f12840297e8d8d39e954078748a1f478841e967e64e6b16b79cf12e' 
  AND token = 'V7pDzphjzctNAqOF+gYx0lyU4Dw5vw7aq9dm/yDAsuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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