SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cc0f480284f1bc29e023647290816f3b9ab00d66e9074f49c7c40f3ef745db5e' 
  AND token = 'ui/jpK10pv4gUidVqGHkz/pcjZsLI8WheWCIat/4Z3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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