Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '1d21216ba71a3679b71e46018bcf0c6dda934d23dd619fc3ff2d0cf9aaf1f2d8' 
  AND token = '5FP/+i443OgNMCSE/6VLVh6iMwB0zNkMecBcUAaoB1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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