SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97a00c8bdf6b68686dcf8551027c555e209d59839c52c7abffd9ccbb78425ae5' 
  AND token = 'hAFV5yF4a2mfIZCRvzBzC0WpwlKBsL6iYxc+5h4oGLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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