SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d93def48040ed2a71e525c99b1eed629440bb084f2b7cc1abc3180b166efbdf' 
  AND token = 'WcKkZHXEv2nLHX8BqcIAKqHCtqSpyiqv1jS1NS78DpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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