SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0d4302762bb4c00fe6572bf25bfd635822f05f82034349dbec6507a0c6933fa7' 
  AND token = '/1i8utxKGzS1ndZcxY0qgUo+xxZLR1iK9Yzpi28BqSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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