SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ad4c4e09163f0f46be8866a7ac3bd796b2f3e69299d6b12a29cd97b8f5b566cf' 
  AND token = '9VGBX64roVNHspJmqLlQha6HuI9I8XV89EHadjwDM0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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