SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '58f24935efa30ff1e713a791de6492a4c01ef2ec28f8ec012b573a2dbbd8b51d' 
  AND token = 'XXOV7iZ/QXl4WzmrgmvkBIjIMx95t9JPY3tp+9MyxqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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