SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e481c11898538312bf3b2056dae4e13afceda08ba9e5549bab14f0c13eacd88' 
  AND token = 'YY0XEOqJu67mf6cV6lOoTkjArqEYtgHLCySU/EwTw5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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