SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '4694a2356db4e130fd2991133f3ca79ea50ecea4709cf0f380897caf28d40902' 
  AND token = 'Zia+YJVPBw05Rp4FrouGqY14DGFvbOPDQF2+54eP8E0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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