SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f058c21080e4f844874dd6d659c809b73cf17b7aad1409c1f6d910fa37790f92' 
  AND token = 'oQYeZ7nwj3pi416P9Uzp+eLwGtee15/tX46sPmNMwKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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