SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f341810211e4a7f7bad95b29f0a84603af8fab6d66c97aa762f90ef4b75324f' 
  AND token = '3VnJv/uFYnEUNubx9wz0hJTjRYhyONwMpRsZTU49Gbc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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