SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3640d3222316b5d2d375ee11ffa193893367ad9eff5f4508f519d02bb1926063' 
  AND token = '+uamsBQkHbM/iPPn98XxHaBNbKdk5zMOfCOLf7s+yh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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