SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '19011ab02f74c52518d75b3a58c202fc13fe63527d920899733ac804ee35a484' 
  AND token = 'svE6iF7g87+DHImnNaH8zjdkhvZJWqhRJ7p24e/OcLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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