SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d7cb68c4fe9d1250c33eeab4716cbca177cbe650a310158ed99066045075e6e' 
  AND token = 'mATzTZz8mzYG1XbjccsdpNrpwVzYIUyf1hONingX8lQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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