SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '65f03f5bfa20f6d1c6bf4f1c3446890bf1c9e1fe60fc9f1e063c67e074403762' 
  AND token = 'Db0QTMtrcJBHMfruxe5G0YEvssO4Miowg8BceYclmD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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