SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e98b652cb1e45ca671dafa9fe98b1259bff9095f77ad425a7e86b565c67bf017' 
  AND token = 'd1cLZrQIwyWiloViNYNe4OcpXUnwZUJmoqKmFtzr0Nk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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