SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '1406605d98564b155e8a24324eb63bec0b2b84ec0bbad72c0ed1b251ff50cc8c' 
  AND token = 'Fh7NRtgzui37SQjA2292K7EMUkWxhitBZGRrPoqk95E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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