SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2ee2a42cff84693c0d0ec5f094137a813b7bb2f75f92e3df657ce20808940a47' 
  AND token = 'Um0DU0XanE9bdLnKPFlNjYuC0NC1C1f1p8xkw/p3Fp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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