SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f28af3f91ed32bb4506cb9f54c0625c2a871547f3699923fb68c6d11f52525fc' 
  AND token = 'BmOmHdkIY5QIovwH/JELWtDQhL7Q02yxVviBh8ZOs44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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