SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '32c4a8d8d100e53dadc65d26bcae0a5f4b2c9509c8428a1c8251ff138212e419' 
  AND token = '4UPnF2eJgBw8uZLhtqtF9TBdP7e4vcl+cpFQzEgKbSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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